Polarized change-over contact device



Sept. 12, 1961 PFLElDx-:RER Erm. 2,999,915

POLARIZED CHANGE-OVER CONTACT DEVICE Filed NOV. 7, 1957 Fg.6 NE s Fig.7

1 um gs@ 41 f2 -713- nym m ,Jn/57.95075. i;zdj fZ/e'darz: j

0;@ fafa fijne/e.

United States Patent O g 2,999,915 POLARIZED CHANGE-OVER CONTACT DEVICE Friedrich `Itieiderer and Otto Adam Thiele, Munich- Solln, Germany, 'assignors to Siemens & Halske Aktiengesellschaft Berlin and Munich, a corporation of Germany Filed lNov. 7, 1957, Ser. No. 694,972 Claims priority, application Germany Dec. 21, 1956 `11 Claims. (Cl. 200-93) This invention is concerned with a polarized contact device comprising change-over contact means contained in a protective tubing.

A paper published in The Bell System Journal, November 1953, beginning on page 1393 describes a changeover contact contained in a protective tubing and polarized in predetermined manner by means of two exteriorly disposedr magnets. In the' corresponding structure, the ends of the outer contact springs, which project from the glass tubing, are provided withy two permanent magnets, the magnetic circuit of these magnets being closed each over a fluxguide sheet extending to the magnetically opposite end of the contact.

The present invention' provides a structure which is, as compared with the' known arrangement, very much sirnplified. They change-over contact structure according to the invention comprises a permanent magnet which brackets the outer contact springs, the field of the permanent magnet extending across the working air gap' substantially transverse of the contact springs within a plane defined by the displacement of the change-over contact spring.

The advantage of the contact arrangement according to the invention resides' among others in' the possibility of using only one: permanent magnet and elimination of ux guide means.

The various objects and features of the invention will appear from a description of embodiments which will be rendered below with reference tothe accompanying drawing. In the drawing,

FIGS. 1,- Z and 3 show embodiments comprising a U- shaped permanent magnet;

FIGS. 4, and 6 indicate an embodiment comprising a diametric-ally magnetized cylindrical body; and

FIG.- 7 illustrates an' arrangement for producing the premagnetizat-ion of the switch-over contact spring.

Referring now to FIGS. l, 2 and 3, the permanent magnet may be made in the form of a U-shaped member having legsv which embrace thev protective tubing along an area in which is disposed the working air gap. The structure is shownin FIG. l in side view with some parts in section and in FIG. 2 in sectional view at the' point of the working air gap. The protective tubing 1 contains the two outer contact springs 2l and 3y and the inner switch-over contact spring 4, such contact springs being made of magnetizable material. The U-shaped permanent magnet 5 is disposed at the area of the Working air gap of the three contact springs. The polarization of the permanent magnetS is indicated by the letters N and S. Energizing coils 6 and 7 (FIG. l) are provided for deliveringy the energy required for the actuation of the contact means. i

The arrangement is based upon the following considerations:

The permanent magnet 5 produces in the working air gap a eld whose forces are with proper adjustment equal between the switchove'r contact spring 4 and the contact spring 2 and between the spring 4 and contact spring 3, respectively. The switch-over spring 4, accordingly, remains in its normal or resting' position. If a further iield is now produced by the energization of the coils 6 and 7, such field, depending upon its direction, will produce 2,999,915 Patented Sept. 12, 1961 ICC amplification of the forces between the switch-over contact spring and one of the outer contact springs while weakening the forces between the switch-over contact spring and the other outer contact spring. Assuming sufficient strength of the field generated by the coils 6 and 7, the inner switch-over contact spring '4 will be attracted by one of the outer contact springs and will establish contact engagement therewith.

The above described arrangement oiers the possibility of effecting an adjustment with simple means or affecting the operating time, respectively. For this purpose, the permanent magnet may be disposed rotatably about an axis extending perpendicular to the plane through the working air gap, which is defined by the motion of the switch-over contact spring. This plane is indicated in FIG. 2 by the dot-dash line.

FIG. 3 shows the structure according to the invention with the permanent magnet 5 in rotated position. A single energizing coil 8 may be employed, which will be sucient provided that adequate energizing force is produced.

In the position of the permanent magnet 5, as illustrated in FIG. 3, there will be a stronger iield between the contact springs 4 and 2v than between the springs 4 and 3, since one of the poles of the permanent magnet, the N-pole in the assumed case, is considerably closer to the contact spring 2 than the S-pole is to the contact spring 3. The permanent flux accordingly extends in this case from the N-pole to the end of the Contact spring 2 and by way of the corresponding part of thev working air gap to the contact spring 4, and thence at least partially as a stray ilux directly to the S-pole, by-passing the contact spring 3. This one-sided amplification of the forces in the working air gap permits equalization of structural inaccuracies and in addition thereto, obtaining diierent operating times. In accordance with the illustrated position of the permanent magnet 5, a shorter time would be required for the actuation of the switchover contact spring 4 in the direction of contact spring 2 than in the direction of contact spring 3.

Rotation of the permanent magnet 5 in opposite direction would produce corresponding but oppositely effective operations.

In the structures illustrated in FIGS. 1 to 3, the switchover contact spring 4 assumes an intermediate position between the two outer contact springs 2 andv 3. This structure presupposes a corresponding stiffness of the switch-over contact spring 4 and strength of the magnetic eld produced by the permanent magnet 5. However, if the magnetic field is increased or the stiffness of the switch-over contact spring 4 is decreased, the latter will ultimately assume a position, referred to as flip-position, in which it is in engagement with one of the two outer contact springs 2V or 3. This operation is due to the fact that the course of the field produced by the permanent magnet is affected by the contact springs for, if the spacing between the switch-over contact spring and one of the outer contact springs is less than the space to the other outer contact spring, the iield strength in the direction of the nearer outer contact spring will automatically increase, resulting in increase of the attractive force in the direction of the corresponding outer contact spring. 'In case of a symmetrical arrangement of the contact springs, both Hip positions may be operative with respect to either one of the outer contact springs.y

In accordance with another object and feature of the invention, there may be provided an embodiment com"- prising a permanent magnet in the form of a diametrically magnetized cylindrical body. Such an embodiment is shown in partially sectional side'view in FIG. 4. IFIG. 5 shows the corresponding structure in cross-sectional view along the working air gap. The permanent magnet 9 is of cylindrical shape and surrounds the protective tubing 1. The polarization of the polarized magnet is indicated by the letters N and S. About the permanent magnet 9 is disposed the energizing coil 10, which may .be Wound upon the permanent magnet or, if it is in the form of a separate coil, may be telescoped over the permanent magnet 9. The switch-over contact spring 4 is shown in a liipped position in which it is in contactmaking engagement with the outer contact spring Z, having assumed this position responsive to the last preceding operative actuation. The change-over spring may be flipped into the alternate position, into contact-making engagement with the outer contact spring 3, responsive to subsequent energization of the coil 10, in which it will likewise remain, pending further energization of the coil 10.

For reasons of eiiicient production, the cylindrical permanent magnet 9 may be formed of a metal sheet, and in such case, there will result an axial slot as shown in FIG. 6, which may be of varying size. The slot should be of a width, such as will permit obtaining a diametrical magnetic eld.

It is in accordance with the invention also possible to Vimpart to the contact a preferential ip position. The

switch-over contact spring may for this purpose be premagnetized; the premagnetization acting in a manner such, as if the energization coil would provide a predetermined permanent ux. Accordingly, the forces in the direction of one outer contact spring will be strengthened and in the direction of the other outer contact spring, they Will be weakened.

FIG. 7 shows a suitable embodiment for producing the premagnetization of the switch-over contact spring. This embodiment comprises, as the one illustrated in FIG. 4, a cylindrical, diametrically magnetized permanent magnet 11, the iield of such magnet extending across the working air gap transverse of the contact springsl in a plane dened by the motion of the switch-over contact spring. A further axially magnetized cylindrical body 12 is placed about the protective tubing 1, such body surrounding the switch-over contact spring 4. In accordance with the vpolarization of the two permanent magnets, as indicated by the letters N and S, there will result a strengthening of the field between the switch-over contact spring 4 and the outer contact spring 2, and a weakening of the iield in the direction of the contact spring 3, thereby imparting to the switch-over contact spring 4 a preferential flip position in which it will be in contact-making engagement with the contact spring 2. 'Ihe energizing coil 13 is placed surrounding both permanent magnets -11 and 12. The energizing coil `13 may be caused to produce a iield opposing the magnetization effected by the permanent magnet 12 and, assuming proper strength of such field, the flux direction with respect to the switch-over contact spring 4 will, accordingly, be reversed, causing such spring to be attracted by the outer contact spring 3 to assume contact-making engagement therewith.

It is, of course, possible to provide a place of the cylin- .drical permanent magnet, a permanent magnet of different configuration; for example, if desired, the switchover contact spring as such may be made of permanent magnet material.

In conclusion, attention may be cal-led to the possibility of rotating the permanent magnet, the field of which extends essentially transverse to the contact springs, about the longitudinal axis of the protective tubing. The result will be a shifting of the Aiiled in the working air gap, making it possible to equalize non-symmetries after assembling the parts.

Changes may be made within the scope and spirit of the appended claims.

We claim:

1. A polarized protective tubing change-over contact arrangement comprising an inner change-over contact spring made of magnetizable material and two outer contact springs also made of magnetizable `inaterialsaid outer springs cooperatively disposed relative to saidvinner contact spring and forming air gaps therewith, said changeover spring being movable in a path for selective contacting engagement with said outer contact springs, and a single permanent magnet having opposite poles bracketing both of said outer contact springs, the eld of said permanent magnet extending across said air gaps of said contact springs substantially transverse thereof in a plane deined by the motion of a line disposed axially on said change-over contact spring.

2. A structure and cooperation of parts according to claim 1, wherein said permanent magnet is of crosssectionally substantially U-shaped configuration.

3. A structure and cooperation of parts according to claim l, wherein said permanent magnet consists of a diametrically magnetized cylindrical body.

4. A structure and cooperation of parts according to claim 1, wherein said change-over contact spring is premagnetized.

5. A structure and cooperation of parts according to claim 3, wherein said permanent magnet is axially slotted.

6. A structure and cooperation of parts according to claim 1, wherein said permanent magnet is disposed rotatable about an axis which extends through the air gaps perpendicular to the plane defined by the motion of said switch-over contact spring.

7. A structure and cooperation of parts according to claim 1, wherein said permanent magnet is disposed rotatable with respect to the longitudinal axis of the protective tubing for said contact springs.

8. A structure and cooperation of parts according to claim 1, comprising an energizing coil surrounding said permanent magnet.

9. A polarized protective tubing change-over contact arrangement comprising an inner change-over contact -spring made of magnetizable material and two outer contact springs also made of magnetizable material, said outer springs cooperatively disposed relative to said inner contact spring and forming air gaps therewith, said change-over spring being movable in a path for selective contacting engagement with said outer contact springs, a single permanent magnet having opposite poles bracketing both of said outer contact springs, the field of said permanent magnet extending across said air gaps of said contact springs substantially transverse thereof in a plane dened by the motion of a line disposed axially on said change-over contact spring, and a further permanent magnet for electing premagnetization of said change-over contact spring, said further permanent magnet being an axially magnetized cylindrical body surrounding said change-over contact spring.

110. A polarized protective tubing change-over contact arrangement comprising an inner change-over Contact spring made of magnetizable material and two outer contact springs also made of magnetizable material, said outer springs cooperatively disposed relative to said inner contact spring and forming air gaps therewith, said change-over spring being movable in a path for selective contacting engagement with said outer contact springs, a single permanent magnet having opposite poles bracketing both of said outer contact springs, the ifield of said permanent magnet extending across said air gaps of said contact springs substantially transverse thereof in a plane defined by the motion of a line disposed axially on said change-over contact spi-ing, and a further axially slotted `'permanent magnet for-med by a cylindrical body suryspring made of magnetizable material and two outer contact springs also made of magnetizable material, said ou/ter springs cooperatively disposed relative to said inner contact spring and forming air gaps therewith, said change-over spring being movable in a path for selective contacting engagement with said outer contact springs, a single permanent magnet having opposite poles bracketing both of said outer contact springs, the field of said permanent magnet extending across said air gaps of said contact springs substantially transverse thereof in a plane dened by the motion of a line disposed axially on said change-over Contact spring, a further axially slotted cylindrical .permanent magnet surrounding said changeover contact spring whereby the :latter is premagnetized, and an energizing yroll surrounding both said permanent magnets.

References Cited in the file of this patent UNITED STATES PATENTS Proctor Dec. 15, 1931 Droysen Apr. 10, 1934 Hufnagel May 9, 1939 Dickten June 10, 1941 Ellywood Mar. 24, 1942 Leveridge May 4, 1943 Garvin May 23, 1950 Brown et al Sept. 2, 1952 George June 25, 1957 Gottfried et a1. Iuly 12, 1958 

